Hand-held electrosurgical instruments, such as electrocautery or laser surgical devices are used in many branches of surgery for the bloodless cutting of tissue, and for the cauterizing of vessels to stop bleeding. During surgical use the localized heat generated by the electrical discharge causes large amounts of noxious smoke to be produced. This high temperature smoke rises rapidly from the point of the cautery instrument. Various studies have indicated that the smoke may contain carcinogenic elements, potentially harmful to the operating room staff. In addition the smoke is sometimes produced in such volume that the surgeon's view of the operative field is obscured. In other circumstances, the anatomy causes the smoke to be trapped. Such a case is the dissection of the left internal mammary artery for subsequent coronary artery bypass grafting. The internal mammary artery lies beneath the left rib cage, several centimeters to the left of the midline incision. The smoke generated during the dissection of the vessel tends to collect in the chest cavity. It is therefore desirable to provide a smoke collection system to remove the nuisance, smell and potential hazard of the smoke. At the same time, the collection system should not unduly interfere with the surgeon's field of view of the tissues being cut, nor can the device interfere with the use of the electrosurgical instrument.
A number of electrosurgical devices are available which do not include any suction capabilities for removing smoke from the operating area. For example, U.S. Pat. Nos. 4,074,718; 4,112,950; 4,170,234; 4,688,569; and 4,986,827. Additionally, other U.S. patents disclose devices which do include suction capabilities. For example, U.S. Pat. Nos. 2,275,167; 3,266,492; and 3,906,955 disclose such devices. These devices include a tube connected to a source of vacuum which runs parallel to the cautery blade. U.S. Pat. No. 4,362,160 discloses an endoscope which includes passages for feeding in and drawing off scavenging or flushing liquid which extends longitudinally behind the cutting or coagulating loop.
It is further known to attach suction means to electrocoagulating devices, as shown in U.S. Pat. Nos. 2,808,833; 2,888,928; and 4,686,981. However, U.S. Pat. Nos. 2,808,833 and 4,686,981 include suction means for the express purpose of withdrawing excess blood prior to coagulating the remaining blood. U.S. Pat. No. 2,888,928 discloses a coagulating surgical instrument which includes a plurality of openings disposed at right angles with respect to the longitudinal axis of the cautery tip. Therefore, the suction operates to clear an area which is not immediately adjacent to the coagulating instrument. Other patents, such as U.S. Pat. Nos. 3,974,833; 4,562,838; 4,683,884; and 4,719,914, disclose an electrosurgical instrument with a smoke dissipating means which is concentric with the cutting blade, or in the case of U.S. Pat. No. 3,982,541, concentric with the laser beam passage. U.S. Pat. No. 5,181,916 discloses a surgical probe and smoke eliminator that incorporates either an annular suction port for laminar air flow intake or a series of circumferentially arranged nozzle orifices configured to create a vortex in the immediate vicinity upstream of distal end of the probe. The nozzle orifices are angularly arranged, as opposed to the longitudinal arrangement of the annular suction port, to induce rotary motion of the smoke in the space around the probe target area.
The processes using electrosurgical devices such as cauterization, laser surgery, and coagulation, are very different procedures. Cauterization involves the use of a hot iron, an electric current or a caustic substance to destroy tissue. Laser surgery involves the use of a precisely controlled laser beam to cut or destroy tissue. Coagulation deals with the process of blood clot formation.
Although the various patents dealing with these devices disclose the general principle of providing a suction passage to the cutting or business end of the device, their particular constructions create difficulties in their use. Namely, they are limited by their structure to removing smoke which is close to the inlet of the suction means. In particular, the structures are such that the vacuum input tube remains very close to the tip of the electrocautery blade generating the smoke. Thus, the surgical field may be obscured from view either by smoke, or by the vacuum input tube itself. In those patents in which the vacuum input tube is far from the cutting surface, the suction is likely to be ineffective in removing all smoke form the surgical field because of the distance between the vacuum input tube and the cutting surface.
Further, in a number of these prior art devices, it is not possible to effectively remove the smoke because the suction tube or passage becomes clogged with blood. It is of the utmost importance that smoke created by the electrocautery, laser surgical or coagulation device be efficiently removed from the surgical field. Smoke created by these devices is suspected of being carcinogenic and mutagenic. Thus, it is necessary to remove the smoke from the surgical field to insure the safety of the surgery team. U.S. Pat. No. 4,963,134 discloses a laser surgery plume evacuator with an aspirator. The evacuator is not connected to a standard wall vacuum receptacle in an operating room (OR). Instead, the evacuator is connected to a self-contained portable unit that includes a source of vacuum. The evacuator includes an intake nozzle which sucks in the plume but which does not form part of the surgical probe. Therefore, the nozzle must be separately handled and may interfere with the surgeon's manipulations of the probe. Also, instead of exhausting the plume through the OR standard wall vacuum, it must be purified and filtered and again exhausted into the OR environment. Therefore, unless purification is complete, the offensive or contaminating substances are re-released into the OR. A similar stand-alone laser plume evacuation system is disclosed in U.S. Pat. No. 5,047,072. Both aforementioned patents disclose control over the vacuum source so that the amount of suction at the suction wand can be modified.
The smoke created by these devices must also be efficiently removed from the surgical field because it obscures the surgeon's view of the surgical field and is an irritant to the surgeon's eyes. The smoke is odorous and interferes with the surgeon's concentration during the operation.
U.S. Pat. Nos. 818,891; 3,394,533; and 3,495,385 disclose devices that include helical shaped members through which fluids flow, although none of these patents discuss the use of a helical element for smoke removal.